Portable digital devices, such as digital cameras, digital camcorders, MP3 players, hand-held PCs, PDAs and the like are widely used and therefore increase the demand for removable storage devices. One type of removable storage device is the flash memory storage device.
With the advent of new technologies and rapid diversification of electronic apparatuses, the market for removable storage devices used in computers and electronic utilities has developed accordingly. Because the portable digital devices require large-scale memory with high quality, demand for inexpensive and large scale removable storage devices is expanding explosively. On the other hand, the diversification of electronic articles has brought about many kinds of technological problems. Even though the flash memory used in most portable devices has advantages with respect to the re-recording and storing of data, it is relatively expensive. Also, due to problems in manufacturing processes used to produce flash memory devices, a reduction in the prices of such devices cannot be expected in the near future.
Flash memory types of removable storage devices include compact flash cards, smart media cards, multimedia cards, secure digital memory cards (or “SD” memory cards) and memory sticks. However, these are not all compatible with one another. Among these removable storage devices, the multimedia card, the SD memory card and the memory stick all have copyright protection functions. However, the SD memory card has shown some advantages as compared to other types of storage devices with respect to data transmission efficiency, etc. SD memory cards are electrically connected to digital devices via a memory card socket. Because a conventional socket for receiving an SD memory card retains the SD memory card within the socket port only by the elastic contact force between electric connecting terminals in the memory card and mating terminals in the socket, the SD memory card can be separated from the socket in conditions that involve large amounts of vibration and impact.
In order to prevent this separation, the use of a cover for preventing the card from separating has been recommended. However, not only conventional cards but module-type cards may be used. The prevention of card separation from the socket is not easily effected with a module-type card due to the size and weight of the module-type card.
Also, because the conventional socket for the SD memory card has separate fitting nails at both sides of the socket housing to fix the SD memory card on a printed circuit board, additional assembly operations added to the manufacturing process of the socket contributes to cost increases and a reduction in productivity.